云冈石窟水分来源控制因素
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摘要
水患和表面分化已经成为威胁我国石质文物的重要问题。云冈石窟位于大同市以西武州山南崖,开凿于砂岩中,石窟内的石雕面临着持续加重的风化损害。各种来源的水是引起石窟雕刻风化最直接也是最根本的因素之一,解决石窟雕刻继续风化的根本出路是准确探测石窟内部的水分进入通道。本文通过调查分析找出各种水分来源的控制因素,为石窟水患治理提供科学依据。
云冈石窟水分来源主要有窟顶或窟壁直接渗水,窟壁泥岩上层滞水入渗,空气中的凝结水等。
影响窟顶渗水的主要因素是降雨量、粉土层厚度,窟顶裂隙发育情况等。粉土层的渗透性远远低于砂卵石,且粉土的滞水能力更强。通过雨后对粉土入渗情况的调查表明,降水不是在任何部位都可以入渗至基岩顶部,只有在粉土较薄的区域才能入渗到基岩顶部。入渗到基岩顶部的水能否进入洞窟与基岩顶部裂隙的发育情况息息相关。砂岩顶面年平均入渗量极少,降水多以径流和蒸发蒸腾方式排泄。
上层滞水的量与泥岩的大小和分布范围有关。也与降水入渗系数有关,随着降水入渗系数的增大而增大。南北剖面图显示泥岩与洞窟有接触,极易形成上层滞水并从洞窟内排泄。
控制凝结水生成的主要因素有气温,地温,空气湿度,风速等,云冈石窟窟内风速全年较低,故影响凝凝结水生成的主要因素为气温与地温之间的温差和空气湿度。夏季气温与地温温差较大,湿度也较高,易产生凝结水,冬季温差小,湿度低,不易产生凝结水。洞窟外壁气温与地温之间温差较小,一般不会产生凝结水。
岩壁上的凝结水量与岩壁的风化程度密切相关,风化程度高的岩壁,由于风化作用使砂岩中孔隙增大,增多,使得风化岩壁比新鲜岩壁凝结面更大,加之岩壁内部温度比表面温度低,故风化岩壁比新鲜岩壁能凝结更多的凝结水。
Flooding and the threat of differentiation has become an important issue of stone artifacts. Yungang Grottoes Stated at south cliff of wuzhou mountain,west of Datong . The Grottoes was dugged in sandstone. The weathering damage of stone caving in face of continued increase. The most directed and fundamental fator of stone weathering is the water from everywhere. The way of solution the caving weathering is detected out the channel of water came into caves. By investigating. we find out the controlling factors of water sources, which provide a scientific basis for caves protection.
The water sources of Yungang Grottoes mainly contain direct seepage from cave top or wall, perched water from mudstone of cave wall, condensation of air.
The main factors affected rainfall seepage to grottoes are thickness of silt, fractured and so on. Permeability of silt is far below to the sand and gravel. in addition, the water storage capacity of silt is more high. The survey of silt infiltration illustrate that don’t every part of rainfall can infiltration to the top of bedrock, only the thin area of silt can. Weather the water enter to the caves related to the development of cracks. The average infiltration of sandstone was minimal, the excretion of precipitation are runoff and evapotranspiration.
The quantity of perched water is related the size and distribution of mudstone, and also related with the infiltration of precipitation. North-South profile shows that mudstone in contact with the cave is easy to form perched water and discharge to the cave.
The main factors of control condensation generated are air temperature, ground temperature, air humidity, wind speed, and so on. The wind speed of Yun Gang grottoes is low throughout the year, so the main factor of condensation generate is the difference between air temperature and ground temperature, air humidity. In summer, the difference between air temperature and ground temperature is small, the humidity of air is high, so easy to generate condensation.
The quantity of water condensation on the cliffs and rock is closely related to the degree of weathering, a high weathering rock, owing to the porosity of weathering sandstone are more, so than the condense surfaces is more big than the fresh rock .combined with that rock internal temperature is low than surface temperature, so the weathered rock condensate more condensation than the fresh rock .
云冈石窟水分来源主要有窟顶或窟壁直接渗水,窟壁泥岩上层滞水入渗,空气中的凝结水等。
影响窟顶渗水的主要因素是降雨量、粉土层厚度,窟顶裂隙发育情况等。粉土层的渗透性远远低于砂卵石,且粉土的滞水能力更强。通过雨后对粉土入渗情况的调查表明,降水不是在任何部位都可以入渗至基岩顶部,只有在粉土较薄的区域才能入渗到基岩顶部。入渗到基岩顶部的水能否进入洞窟与基岩顶部裂隙的发育情况息息相关。砂岩顶面年平均入渗量极少,降水多以径流和蒸发蒸腾方式排泄。
上层滞水的量与泥岩的大小和分布范围有关。也与降水入渗系数有关,随着降水入渗系数的增大而增大。南北剖面图显示泥岩与洞窟有接触,极易形成上层滞水并从洞窟内排泄。
控制凝结水生成的主要因素有气温,地温,空气湿度,风速等,云冈石窟窟内风速全年较低,故影响凝凝结水生成的主要因素为气温与地温之间的温差和空气湿度。夏季气温与地温温差较大,湿度也较高,易产生凝结水,冬季温差小,湿度低,不易产生凝结水。洞窟外壁气温与地温之间温差较小,一般不会产生凝结水。
岩壁上的凝结水量与岩壁的风化程度密切相关,风化程度高的岩壁,由于风化作用使砂岩中孔隙增大,增多,使得风化岩壁比新鲜岩壁凝结面更大,加之岩壁内部温度比表面温度低,故风化岩壁比新鲜岩壁能凝结更多的凝结水。
Flooding and the threat of differentiation has become an important issue of stone artifacts. Yungang Grottoes Stated at south cliff of wuzhou mountain,west of Datong . The Grottoes was dugged in sandstone. The weathering damage of stone caving in face of continued increase. The most directed and fundamental fator of stone weathering is the water from everywhere. The way of solution the caving weathering is detected out the channel of water came into caves. By investigating. we find out the controlling factors of water sources, which provide a scientific basis for caves protection.
The water sources of Yungang Grottoes mainly contain direct seepage from cave top or wall, perched water from mudstone of cave wall, condensation of air.
The main factors affected rainfall seepage to grottoes are thickness of silt, fractured and so on. Permeability of silt is far below to the sand and gravel. in addition, the water storage capacity of silt is more high. The survey of silt infiltration illustrate that don’t every part of rainfall can infiltration to the top of bedrock, only the thin area of silt can. Weather the water enter to the caves related to the development of cracks. The average infiltration of sandstone was minimal, the excretion of precipitation are runoff and evapotranspiration.
The quantity of perched water is related the size and distribution of mudstone, and also related with the infiltration of precipitation. North-South profile shows that mudstone in contact with the cave is easy to form perched water and discharge to the cave.
The main factors of control condensation generated are air temperature, ground temperature, air humidity, wind speed, and so on. The wind speed of Yun Gang grottoes is low throughout the year, so the main factor of condensation generate is the difference between air temperature and ground temperature, air humidity. In summer, the difference between air temperature and ground temperature is small, the humidity of air is high, so easy to generate condensation.
The quantity of water condensation on the cliffs and rock is closely related to the degree of weathering, a high weathering rock, owing to the porosity of weathering sandstone are more, so than the condense surfaces is more big than the fresh rock .combined with that rock internal temperature is low than surface temperature, so the weathered rock condensate more condensation than the fresh rock .
引文
[1] Andreas Arnold. Methodology of the Study on Decay, Weathering and Conservation of Monuments. Lecture Notes of International Course on the Technology of Stone Conservation, Venice: ICCROM/UNESCO,1997
[2] B.K.Das, M.Singh. Water Chemistry and Control of Weathering of Pichola Lake, Udaipur District, Rajasthan, India. Environmental Geology, 1996, 27:184-190
[3] Fritz, B., and Daniel, J., and Bart,J.C., Petrography and Experimental Geochemical Control of Surface Transformation of Monument Sandstones. Sci. Geol. Bull, 1981,34(4):193-208
[4] Giovanni and Ippolito Massari. Damp Buildings old and new. Rome: ICCROM, 1993:4
[5] Helmut Weber, Klaus Zinsmeiste. Conservation of Natural Stone. Germany: Expert verlag GmbH, Goethestra?e Ehning bei B?blingen, 1991:34-52
[6] Luis Valdeoe, Rosa M.Esbert and Carlota M.grossi. Hydric Properties of Some Spanish Building Stone: A Petrophysical Interpretation. Materials Research Spciety, Vol 267:911-916
[7] M . Laurenzi-Tabasso and U.Santamaria. in Vth int. cong. On Deterioration and Conservation of Stone, 1985:697-707
[8] Michael B.Bever. Encyclopedia of Materials Science and Engineering. PERGAMON PRESS, 1986:3839-3847
[9]M.Vendrell-Saz, M.Garcia-Valles,S.Alarcon.Environmental Impact on the Roman Monuments of Tarragona, Spain. Environmental Geology, 1996,27:263-269
[10]曹文炳,万力.西北地区沙丘凝结水形成机制及对生态环境影响初步探讨.水文地质工程地质,2003,30(2);9
[11]曹文炳、万力.西北地区沙丘凝结水形成机制及对生态环境影响初步探讨.水文地质工程地质,2003,30(2);9
[12]付林森,汪东云,姚金石,等.北山石窟风化产物可溶盐形成的水文地球化学机理张赞勋工程勘察.1996,(02):37-42
[13]黄继忠,史变青,解廷藩,等.云冈石窟大气粉尘中金属离子的分析.雁北师院学报. 1998,(2), 21-24。
[14]黄继忠,解廷藩,张莉.云冈石窟大气粉尘中无机离子的分析.文物世界,1997,(3):86-90
[15]黄继忠,张俊芳.应用电法勘探调查云冈石窟岩体裂隙.文物季刊, 1998.(3):86-90
[16]黄克忠.云冈石窟砂岩石雕的风化问题,水文地质与工程地质,1984,(3):32-35
[17]乐山大佛乌尤保护管理局,四川省文物考古研究所.治理乐山大佛的前期研究.第一版,成都:四川科学技术出版社,2002:14-103
[18]潘别桐,黄克忠.文物保护与环境地质.武汉:中国地质出版社,1992:147-160
[19]尚剑宝,上官学兵.山西大同云岗石窟防水保护方案探讨.山西建筑, 2003,29(6):75-76
[20]石玉成.石窟文物病害成因分析及其对策研究.自然灾害学报,1997,6(1):104-110
[21]任建光,黄继忠,石云龙,等.云冈堡土遗址病害调查及其防治措施建议.山西大同大学学报,2009,25(3):87-90
[22]童登金.大足石刻的水害治理.中国——意大利世界遗产保护技术研讨会.北京,2000
[23]谭科艳.十里河工程对云冈石窟文物保护影响的研究:[硕士学位论文].北京:中国地质科学研究院,2006
[24]汪东云,张赞勋,付林森,等.宝顶山石窟卧佛渗水病害形成原因分析.水文地质工程地质,1992,19(3):25-28
[25]王旭东,李最雄.安西榆林窟的岩土工程问题及防治对策.敦煌研究,2000,1:127
[26]汪东云,刘东燕,张赞勋.摩岩石刻文物保护防风化研究现状及深化方向.重庆建筑大学学报,1997,4(19):106-111
[27]吴宝燕,张爱国,朱丽君,云冈石窟水害及其治理措施,地下水, 2008,30(3):116-118
[2] B.K.Das, M.Singh. Water Chemistry and Control of Weathering of Pichola Lake, Udaipur District, Rajasthan, India. Environmental Geology, 1996, 27:184-190
[3] Fritz, B., and Daniel, J., and Bart,J.C., Petrography and Experimental Geochemical Control of Surface Transformation of Monument Sandstones. Sci. Geol. Bull, 1981,34(4):193-208
[4] Giovanni and Ippolito Massari. Damp Buildings old and new. Rome: ICCROM, 1993:4
[5] Helmut Weber, Klaus Zinsmeiste. Conservation of Natural Stone. Germany: Expert verlag GmbH, Goethestra?e Ehning bei B?blingen, 1991:34-52
[6] Luis Valdeoe, Rosa M.Esbert and Carlota M.grossi. Hydric Properties of Some Spanish Building Stone: A Petrophysical Interpretation. Materials Research Spciety, Vol 267:911-916
[7] M . Laurenzi-Tabasso and U.Santamaria. in Vth int. cong. On Deterioration and Conservation of Stone, 1985:697-707
[8] Michael B.Bever. Encyclopedia of Materials Science and Engineering. PERGAMON PRESS, 1986:3839-3847
[9]M.Vendrell-Saz, M.Garcia-Valles,S.Alarcon.Environmental Impact on the Roman Monuments of Tarragona, Spain. Environmental Geology, 1996,27:263-269
[10]曹文炳,万力.西北地区沙丘凝结水形成机制及对生态环境影响初步探讨.水文地质工程地质,2003,30(2);9
[11]曹文炳、万力.西北地区沙丘凝结水形成机制及对生态环境影响初步探讨.水文地质工程地质,2003,30(2);9
[12]付林森,汪东云,姚金石,等.北山石窟风化产物可溶盐形成的水文地球化学机理张赞勋工程勘察.1996,(02):37-42
[13]黄继忠,史变青,解廷藩,等.云冈石窟大气粉尘中金属离子的分析.雁北师院学报. 1998,(2), 21-24。
[14]黄继忠,解廷藩,张莉.云冈石窟大气粉尘中无机离子的分析.文物世界,1997,(3):86-90
[15]黄继忠,张俊芳.应用电法勘探调查云冈石窟岩体裂隙.文物季刊, 1998.(3):86-90
[16]黄克忠.云冈石窟砂岩石雕的风化问题,水文地质与工程地质,1984,(3):32-35
[17]乐山大佛乌尤保护管理局,四川省文物考古研究所.治理乐山大佛的前期研究.第一版,成都:四川科学技术出版社,2002:14-103
[18]潘别桐,黄克忠.文物保护与环境地质.武汉:中国地质出版社,1992:147-160
[19]尚剑宝,上官学兵.山西大同云岗石窟防水保护方案探讨.山西建筑, 2003,29(6):75-76
[20]石玉成.石窟文物病害成因分析及其对策研究.自然灾害学报,1997,6(1):104-110
[21]任建光,黄继忠,石云龙,等.云冈堡土遗址病害调查及其防治措施建议.山西大同大学学报,2009,25(3):87-90
[22]童登金.大足石刻的水害治理.中国——意大利世界遗产保护技术研讨会.北京,2000
[23]谭科艳.十里河工程对云冈石窟文物保护影响的研究:[硕士学位论文].北京:中国地质科学研究院,2006
[24]汪东云,张赞勋,付林森,等.宝顶山石窟卧佛渗水病害形成原因分析.水文地质工程地质,1992,19(3):25-28
[25]王旭东,李最雄.安西榆林窟的岩土工程问题及防治对策.敦煌研究,2000,1:127
[26]汪东云,刘东燕,张赞勋.摩岩石刻文物保护防风化研究现状及深化方向.重庆建筑大学学报,1997,4(19):106-111
[27]吴宝燕,张爱国,朱丽君,云冈石窟水害及其治理措施,地下水, 2008,30(3):116-118